Many child-resistant caps and closures have been suggested in recent years because of the greater activity directed towards insuring that dangerous and poisonous materials be packaged in containers which are significantly difficult for small children to open.
Exemplary of the containers and closures developed by the art in response to this need is the closure and container shown in U.S. Pat. No. 3,888,376. This container and closure is in the class of child-resistant packages which feature latching and unlatching means carried by the threads of the closure and the container. Generally, this class is beset by the problem of requiring very exact container and closure manufacture so that registration of the latching structure can be predictably effected. The manufacturing standards required are oftentimes difficult to achieve when it is considered that the packager oftentimes purchases the containers from sources separate from the closures.
Despite these difficulties, however, this class of child-resistant closure and container is highly desirable in that the locking mechanism is carried internal to the package when the closure is fitted to the container. Other classes of child-resistant closures and containers which rely upon exterior locking systems oftentimes are not entirely satisfactory as a child is free to attack the locking structure.
Therefore it is an object of this invention to provide a container and closure which is child-resistant, which is in the class of containers and closures which have the locking systems carried by the threads of the containers and closures, and which is able to achieve its child-resistant locking position even when manufacturing tolerances are kept far below precise levels.